Grinding apparatus



Dec. 29; 1925- 1, 7

R. we. JOHNSTONE GRINDING APPARATUS Filed April 4, 1921 5 sheets-Sheet l Dec 29, 1925. 7

R. M C. JOHNSTONE GRINDING APPARATUS Filed April 4, 1921 5 Sheets-Sheet 2 MINIMUM wilhmuimm Snow/I101 Dec. 29, 1925. 1,567,272

R. M C. JOHNSTONE GRINDING APPARATUS Filed April 4, 1921 5 sheets-Sheet 5 51 vwewfoz 351 A; Gr f W Dec. 29,1925. 1,56%,272

M C. JOHNSTONE GRINDING APPARATUS Filed pril 4. 1921 5 Sheets-$heet 4 R. M C. JOHNSTONE GRINDING APPARATUS Filed April 4, 1921 5 Sheets-Sheet 5 of a cutter work holder swung into 7 the workholder. videc l-for so moving these two-elements with Patented Dec. 29, 1925.

UNITED STATES 1,567,272 PATENT OFFICE.

ROBERT M00. J'OHNSTONE, 0F ROSELIJE PARK, NEW JERSEY, ASSIGNOR TO CAMERON MACHINE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

GRINDING APPARATUS.

Application filed April 4, 1921. Serial No. 458,443.

To all whom it may concern Be it known that I, ROBERT MoC. J OHN- STONE, a citizen of the United States, and a resident of Roselle Park, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Grinding Apparatus, of which the following is a specification.

This invention relates to grinding ma chines and has for its main object and feature the production of a machine that will accurately grind opposite sloping surfaces having aperipheral cutting edge.

Fig. 1 is a front elevation of a grinding machine embodying the invention, with parts broken away.

Fig. 2is a top plan view of themachine shown in Fig. 1 with the work holder swung into oneposition.

' Fig. 3 is a; horizontal sectional view on the plane of line 3-3 of Fig. 1, with the another position.

:Fig. 4 is a detail sectional view on the plane of line 4-4 of Fig. 3. Fig. 5, is a vertical sectional detail View substantially on the plane of line 5-5 of .Fig. 3.

Fig. 6 is a detail vertical sectional vView on theplane of line 6- 46 of Fig. 5.

Fig. 7 is a horizontal sectional view on' the plane of line 77 of Fig. 6.

. Fig. 8 is a horizontal section through the work holder and adjacent elements.

Fig. 9 is a horizontal sectional view of a modified-form of cutter holder.

Fig. 10 is a plan view of a modified form of'work'holderj. I

Fig. 1-1 is adiagrammatic view showing r l l' l relation grinding element and 2 is -S u1table means are pro- 1 'indicateslthe respect to'eaoh other that different angular faces of the work may be brought into parallelism-or other proper relation with the plane of the face of the grmding'element.

Obviously, either the work holder or the grinding element may be moved with respect to the other, or both may be so moved, to accomplish this result. stance, the work to be ground or sharpened is a circular cutter 3 having a relatively blunt peripheral cutting edge 4 produced by two angular faces 5 and 6. A circular cutter In the present in- 2-; is substantially in line of the workto theltgrindingof this character is known as a score-cutter and is here intended to be used as a slitting element in a machine for slitting and winding paper such as is shown, for instance, in Patent No. 1,076,189 of October 21, 1913. It will be understood that it is highly desirable that the cutting edge be equidistant from the sides of the cutter in order that the paper may be slitted at the correct point; and, in this case, it is therefore important that the angles of faces 5 and (i be the same with respect to a median l1ne,- that is, the cutting edge of the disk.

In the embodiment of the invention here shown it is preferred to mount the work holder 2 so that it may be swung to bring faces 5 and 6 parallel with the peripheral face of the grinding element 1. To this end, work holder 2 is pivotally mounted on pivot 7 and is provided with suitable means for supporting the work, this means, in the present instance, taking the form of a bearing 8 that supports a spindle 9 on which the uprights 17, by means of belt 18 and, in order that transmission of power to pulley 11 may be effected in any of its adjusted positlons without the necessity of lengthening or shortening said belt, pivot 7 of work holder with pulley 14. From thisjit will be understood that the transmission means adjusts itself automatijcally to correspond to the adjustment of the work holder. It will be noted from Fig. 11 that the center of rotation indicated by pivot is not coincident with the face of the grinding element so that, when swinging the work holder, the cutting edges of the cutter will move away from the grinding element, as indicated in dotted lines, and will then move back again as it approaches its other position. It will also be noted from Fig. 8 that the median line defined by cutting edge 4 is substantially radial with respect to pivot 7 To avoid the necessity of careful adjustment-when swinging the work holder from one position to another and, at the same :faces :is to be Z ground.

stantially radial indicated "a bore corresponding to+bearing and, m either case,

' 1. This eccentric f bushing with teeth '26 "and a screw "to engage these time, to insure parallelism between the face to be ground and the grinding element, means are provided for obtaining definite angular adjustments of the work holder These means here take the form of stops 19 and 20 on the framework and angular abutment faces 21 and22 on the work holder. These angular abutment faces bear a definite relation to faces right angles thereto and extend with respect to'the center of rotationafforded by spindle 9 at an angle equal to the angle between the median line defined by cutting edge a and faces 5 or 6. Thus, if faces 5 and 6 are thirty degrees from a linepassing through cuttingedge 4i, abutment faces 21 and 22 are thirty degrees from the axisof sp1ud'le'9. If, as shown in Fig. 9, faces 5 and 6 are 'IfOI'tYfiVG degrees from a' line passing through cutting edge 1*, then, as shown in :Fig. '10, abutment faces 21 and '22 are forty-five degrees from :line 9 indicating the aXis of rotation of the work. These different results-may, of-course, be obtained by attaching different angular abutment faces to the work holder but, in the present case, it is preferred to substitute different work holders when work'having different angular It is customary in :different'size slitting'machines to have cut :t'ers o'f different si:ze,-that is, cutters of variousthicknesses. In order-that'the line' definingthe cutting-edged maybe always subto pivot 7, advantage is taken ofthe' fact-- that different thicknesses ferenti bearing surfaces, such as 23 and' 241, :thatfit the different bores o'f-the cutters. Thus, as shown in Fig. 8, a cutter of'the size has a bore=corresponding to beara-ithinner cutter wi'l-l'have surfacei2i :the median line defined by cutting edge 1 will-be substantially radial'with respect to-pivot 7. Pivot'7 is seated in an eccentric bushing :25 -:so I that ing surface 23 and should there be aldiscrep'anc'y, due-to wear of the partslor. other causes, it can be ad juste'dto shift the work ho1'der..-a ndthereby also the :median line defined by: cutting edge 25" is provided -ed. Cutters also vary as to their diameters because of di'fierences in size which exist sometimes for-a purpose and again are due to wear.- For this, and other reasons presently to be explained, it is desirable that the .work holder be moved at rlght angles to face 5 111 Fig. 8 so as to bring said-face toward or away from the face of the grinding element 1,. carried by a slide 28 movable in guides 29 5 and 6 in that they are at 'is' grasped and the work .pivot 7 as. by means of a threaded stem 30 rotatable in a base plate 31. 32 indicates a raised track on base plate 31 on which the work holder travels as it is swung. To protect receptacle 34 provided with a bottom partition 35 covering the pivot, is provided.

Grinding element 1 is rotatably mounted on shaft 36 which is carried by a housing 37, square in cross section, and sllida-bly mounted in open face'bearing blocks 88, so that the housing, with the shaft, is movable parallel to the angular face of the work to be ground, or lengthwise of the axis of the shaft. Shaft 36 is enclosed in "the housing to protect it from dust; and thelsliding movement of the housing is limited by surfaces 39 coming in contact with straps 100 spanning bearings 38.

Shaft'36 carries a pulley 10 that receives motion from pulley l1 on counter-shaft 15 by 'meansof belt 12 which-is sufficiently flexible to admit'of the sliding motion of houslidotionmay be supplied to countershaft '15 in any suitable way, as by means of a loose and tight ipulley but, in the present instance,

'itis preferred to employ an electric motor-43 having a pulley 44 and a belt 45 passing over pulley lG of the countershaft.

In :practice, the cutter having been mountedon spindle 9, handle-a7 of the work holder holder is moved into the positionlindicated in Fig. 2 Where it remains until face f the cutter has been sufiicientl y' ground. During this action, abradingwheel 1 and cutter 3 are rotated,

"preferably in opposite directions with requite touch parts will spect to-each other, and the operator may a l-so slide abrading wheel 1 back and forth lengthwise of its axis. -By preference, the

be so arranged that When abutment faceg22 strikes stop 20, face 6 willnot the grinding element and knurled piece 48 will then be rotated to actuatethreaded stem 30 and thus press face 6 against the abrading surface. It will be understood, however, that approximately the gsam'e efiect may be obtained by pressing against handle 47. It will also be noted-that aabutmentface 2251s so'related tostop 20 that the iwork: holder is free to slide at right I 27 maybe used teeth to retain the parts in J a posltion' to which they have been adjust .Fig. 3,-when face 5 is ground. To keep To accomplish this, pivot 7 is angles to the grinding face of the abrading wheel when moved. under the influence of threaded-stem 30. The same thing is true "of stop 19 and abutment surface 21. When the grinding facc, handle 17 is grasped and the work operation is finished on one holder is swung to the position indicated in the' trac'k' 32 clean, the work holder may be provided with felt cleaners 19.

I claim:

1. Grinding apparatus comprisin a grinding clen'ient, a work holder, 2). plvotal" from dust, adust box 33, having a I support for the work holder whereby said work holder may be swung with respect to the grinding element to effect different angular grinding relations between the two, and an adjustable eccentric bushing surrounding said pivot.

2. Grinding apparatus for cutters comprising: a grinding element, a work holder, a pivot on which the work holder swings, a rotatable work support for holding a cutter having aperipheral cutting edge and oppositely beveled sides, and means for adjusting the work holder to bring a median line through the cutter radial with the pivot so that the grinding action will be equal on both beveled sides and to bring the peripheral cutting edge of the cutter coincident with the median line through the cutter.

3. Grinding apparatus for cutters comprising: a grinding element, a work holder, a rotatable work support for holding a cutter having a peripheral cutting edge and oppositely beveled sides, a pivot on which the work holder swings to bring oppositely beveled sides of the cutter into grinding relation with the grinding element, stationary stops on the frame, and angular abutment surfaces on the work holder to cooperate with said stops and to thereby determine the angle of grinding.

4. Grinding apparatus for cutters comprising: a grinding element, a work holder, a rotatable work support for holding a cutter having a peripheral cutting edge and oppositely beveled sides, a pivot on which the Work holder swings to bring oppositely beveled sides of the cutter into grinding relation with the grinding element, stationary stops on the frame, and abutment surfaces on the work holder to cooperate with said stops, said surfaces being at an angle to the center of rotation of the work support and the angle of grinding being equal to the angle between the axis of the work support and the abutment surfaces.

5. Grinding apparatus for cutters comprising: a grinding element, a work holder presenting different angular abutment surfaces at will, a rotatable work support for holding a cutter having a peripheral cutting edge and oppositely beveled sides, a pivot on which the work holder swings to bring oppositely beveled sides of the cutter into grinding relation with the grinding element, stops on the framework to engage the abutment surfaces to thereby limit the swinging movement of the work holder so that the angle of grinding may be determined by varying the angular relation between the axis of rotation of the work support and the abutment surfaces on the work holder.

Signed at Brooklyn, N. Y., in the county of Kings and State of New York, this 28th day of March 1921.

ROBERT MoC. J OHNSTONE. 

